3GPP mainly formulates globally applicable technical specifications and reports for a 3rd generation mobile communications system. All 3GPP architecture-based networks may be referred to as 3GPP networks, for example, a 3GPP framework-based mobile communications network.
A 3GPP network may provide a basis for communication between mobile terminals, and has advantages of wide signal coverage and relatively high mobility performance but has a relatively low data transmission rate. A non-3GPP network such as a WLAN (wireless local area network) may provide hotspot coverage, and is characterized by a relatively high data transmission rate but relatively low mobility performance. Therefore, if the 3GPP network and the non-3GPP (non-3GPP) network are combined, user experience can be improved, network construction costs can be reduced, and fewer radio resources are required.
UE (user equipment) may directly access a 3GPP network or may access a 3GPP network by using a non-3GPP network. A core network device determines whether the UE is authorized to access the 3GPP network. If determining that the UE is unauthorized to access the 3GPP network, the core network device generates an unauthorized access message and sends the unauthorized access message to the UE. However, the UE still attempts to access the 3GPP network. It is assumed that 500 thousand users attempt to access the 3GPP network, and that 400 thousand users cannot access the 3GPP network because they do not have access permission, that is, an HSS sends an unauthorized access message to the 400 thousand users. However, the 400 thousand users still attempt to access the 3GPP network, resulting in excessively heavy load of the core network device.